[Date Prev][Date Next]
[Chronological]
[Thread]
[Top]
Re: [PSUBS-MAILIST] Sensor Interfacing
That is also how the MSP430 will communicate. I have
used both series of products, and the MSP430 is
faster,
cheaper, easier to use, consumes less power, and is
extremely reliable. I am unaware of any other system
that can match the MSP430s for reliability. I have had
the Maxim devices randomly fail, permanently, for no
apparent reason...Not kosher under 300' of water...
Warren.
--- Michael Wright <mwright@smallip.com> wrote:
> For interfacing sensos to a PC I would look at the
> Dallas/Maxim IC
> 1-wire equipment. The devices connect to the PC via
> serial port.
>
> http://www.embeddeddatasystems.com/
>
> for I/O Devices:
>
>
http://embeddeddatasystems.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=IO
>
> One advantage of going with 1-wire is that since
> 100+ devices connect
> via a 1-wire plus ground network it limits the
> number of hull
> penetrations needed.
>
> http://www.maxim-ic.com/1-Wire.cfm
>
>
> I haven't used National Instruments Products because
> they were simply
> beyond the budget for what we were doing.
>
>
> If you want to build your own interface I would note
> that having used
> the BasicX and PIC-Basic Pro (a lanuguage identical
> to basic stamp 2) I
> would not consider using anything based on Basic
> Stamp. BasicX uses
> BXBasic, which is VB 6 with most of the stupidity
> removed. The cost for
> a BX Kit is $100 and the IDE is free.
>
> The Netmedia BasicX units were quite effective for
> the vehicle
> Depth-Heading systems and remote monitoring
> applications I used them
> for. Though the BasicX units can multitask, their
> limited RAM (400
> bytes) makes it something to be careful of. I would
> also note that
> their on board serial port does 0V to 5V signalling
> rather than true -5V
> to +5V, which is only a problem if you were
> connecting it to a dumb
> device (such as a Fiber-Optic transceiver) and can
> be solved by putting
> a maxim RS232 chip inline.
>
> If you already program in C or have time to learn,
> don't pay the extra
> money for the limitations of anything programmed in
> any basic variant.
>
>
> All that said I would also note that one of the
> design constraints I was
> under was that the systems had to be adaptable to
> work standalone (no
> PC). Given the option of a scratch redesign with a
> PC, I'd use 1-wire
> sensors directly to it (well probably four seperate
> 1-wire networks (2
> redundant for outside the hull and 2 redundant for
> inside the hull).
>
> Good Luck,
>
> mike
>
> Warren Greenway wrote:
>
> > This one I know, since I am an embedded systems
> > engineer. First, the direct to PC interface will
> be
> > either one of the most expensive, or one of the
> most
> > difficult you can tackle. Second, yes, there are
> > hundreds of options in the way of PCI boards (not
> AGP,
> > that is graphics). Interfacing through the RS232
> Port
> > is what I would recommend. This is the easiest,
> > cheapest
> > and most flexible. To do this, you will need some
> > basic
> > electronics and programming skills (or you get
> back to
> > VERY expensive). The code and hardware is very
> simple
> > if you go with the MSP430F1121 (or related
> MSP430).
> > This
> > is the easiest series of MCUs to program. The
> devel
> > kit is $49 from TI. They have ADCs and UARTs built
> in.
> > You simply fire up the ADC, take a reading, fire
> up
> > the
> > UART, and transmit the reading to any RS232 device
> you
> > want. You can also recieve and execute control
> > commands.
> > This may sound a little wild, but believe me you
> get
> > the most bang for your buck in the MCU world.
> Another
> > simpler, and much less powerfull option would be
> the
> > Basic Stamp or BasicX. Both of these can also
> provide
> > a cheap interface to your PC.
> >
> > Warren.
> > --- peter mckellar <mckellar@earthlink.net>
> wrote:
> >
> >>Hi,
> >>
> >>Apologies in advance for shamelessly displaying
> the
> >>depths of my ignorance. I have a general question
> >>on interfacing sensors to PCs.
> >>
> >>I know that many of the control systems built by
> >>contributors are custom PLCs etc. I also know
> that
> >>many pressure sensors, oxygen guages are
> mechanical
> >>and avoid these problems.
> >>
> >>I however was hoping to use (basically)
> >>off-the-shelf components hooked into a standard
> PC.
> >>Is this even possible?
> >>
> >>What I'm talking about is standard PC boards that
> >>slip into a PCM, AGP etc type slot and they have a
> >>wire attached to a probe that is either naked or
> >>mounted somewhere in the cabin, or stuck through
> the
> >>hull.
> >>
> >>Todays research has centred around sensor
> suppliers
> >>(specifically ceramic, piezo-electric or MEM based
> >>at this stage) but I can't seem to fathom how
> these
> >>are interfaced.
> >>
> >>1. Is there a standard PC board protocol/usb
> >>attachable mulitplexor that allow me to buy
> sensors
> >>and attach them either individually, daisy-chained
> >>or as part of a sensor array, mixing and matching
> as
> >>I desire?
> >>
> >>2. Is there standard software (maybe html based?)
> >>that comes with these like they supply for
> routers,
> >>or for that matter, is ANY software ever supplied
> >>with these devices?
> >>
> >>3. do any come with an IP address that allows me
> to
> >>plug them straight into an onboard lan
> >>
> >>I can see this could get really ugly :( i can do
> >>wonderful things with software, flip bits, do
> >>boolean stuff, draw truth tables, but i've never
> >>burnt a rom in my life and can't even solder :(
> >>
> >>I guess I'm wondering if I can do plug-n-play
> things
> >>or if I should look at enrolling in an electronics
> >>(hands-on) course.
> >>
> >>Any suggestions or comments?
> >>
> >>peter
> >
> >
> >
> > __________________________________
> > Do you Yahoo!?
> > Yahoo! SiteBuilder - Free, easy-to-use web site
> design software
> > http://sitebuilder.yahoo.com
>
>
__________________________________
Do you Yahoo!?
Yahoo! SiteBuilder - Free, easy-to-use web site design software
http://sitebuilder.yahoo.com